As one of the five major theoretical and practical issues raised by the Central Economic Work Conference, "to correctly understand and grasp the supply security of primary products" is an important path to ensure the realization of national food security strategy and energy security strategy. Starting from the major strategic needs of the country, management practice and scientific cognition, we systematically sort out the understanding of primary mineral products at home and abroad, form the definition and scope of primary mineral products based on the major strategic cognition, and put forward the concept of primary mineral products. We classify primary mineral products by production and consumption links, and take iron ore, iron concentrate and crude oil as examples to identify the differences and key nodes of primary mineral products, midstream mineral products and downstream mineral products in the industrial chain and supply chain. We summarize and present several economic relations of primary mineral products under the requirements of the new era, so as to provide theoretical support for implementing the national energy security strategy, the supply and guarantee services of primary mineral products, and the research work of primary mineral products.

To clarify the rare earth demand growth driven by global rapid expansion of wind power under carbon neutrality and make the rare earth resource strategic planning for wind power development, this paper intends to predict global 10 major countries and regions' rare earth demand for wind power development by 2040 through material flow analysis, studies the implications of technology progress and recycling on rare earth supply and demand structure, and explores the advantages and issues of China's rare earth industry under carbon neutrality. Our results show that: 1) carbon neutrality climate target will bring about a rapid expansion of global demand for rare earth elements, which is about twice that under the stated policies; 2) global wind power development will lead to severe rare earth supply pressure, and material technology progress and recycling will play important roles in alleviating this pressure; 3) China will still occupy a leading position in the global rare earth industry chain in the next 20 years, but face competition and challenges from global diversified rare earth suppliers, such as Australia, Myanmar, Vietnam, North America, etc. We propose that China should coordinate "two resources" and "two markets" at home and abroad, make full use of the advantages of rare earth processing industry agglomeration, strengthen technological competitiveness of highperformance magnet materials and their related industries, and accelerate the construction of rare earth permanent magnet recycling industrial chain.

To understand the whole industry chain of cerium, expand its application field and increase its potential value， a dynamic material flow analysis (MFA) framework for cerium is established in this study. It takes 1990—2018 as the time boundary and the Chinese mainland as the spatial boundary. The cerium in each link is simulated and the trade pattern of cerium in China is analyzed. The results are the followings. 1) from 1990 to 2018, China was the largest supplier of cerium and the cumulative supply to the world was 750000 t; the cumulative domestic consumption was only 390000 t and the external cumulative export volume was 220000 t, there is a surptus of 140000 t. 2) the application of cerium products involved all kinds of rare earth products, of which catalysts and alloys were the two largest application sectors, and the cumulative consumption between 1990 and 2018 was 120, 000 and 96000 t, respectively. 3) since 2010 China's cerium export volume has generally decreased and the export form has gradually transitioned from smelted products to processed products, therefore, China should continue to increase investment in scientific research to develop new applications of cerium to ensure market stability continuously. The research results may provide a reference for sorting out the whole industrial chain of cerium, identifying the contradiction between supply and demand, and expanding the application field.

Based on the dynamic material flow analysis method, this study takes 1990-2018 as the time boundary and mainland China as the spatial boundary to analyze the whole life cycle flow of praseodymium. It is found that 1) from 1990 to 2018, China mined more than 100000 t of praseodymium for downstream industrial applications, about 70% of which (68500 t of praseodymium) were used in NdFeB; 2) before 2009, China's praseodymium supply was sufficient (31000 t of unregistered consumption), and after 2009 the supply gap of praseodymium increased year by year (24000 t of unregistered production); 3) both import and export volumes of praseodymium increased, with import being mainly intermediate product of rare earth ores and praseodymium while export mainly intermediate product and final product of praseodymium; and 4) in 2018 the in-use stock of praseodymium exceeded 37000 t, of which 23% were in air conditioners, electroacoustic headphones and magnetic separators, with insufficient recycling. To resolve the problem between supply and demand this study put forward some suggestions, such as improving recycling capacity and technology of praseodymium, optimizing the structure of praseodymium trade, increasing the import of ore and primary products, properly controling export, and exploring NdFeB permanent magnet substitute products.

In order to reveal the changing trend of lanthanum material flow in China and describe its trade pattern, this paper constructs a dynamic material flow analysis framework for lanthanum that simulates the flow of lanthanum in the whole life cycle and analyzes the flow of lanthanum in China in terms of inventory, and supply and demand from 1990 to 2018,. The results show that: 1) 96% of China's lanthanum supply came from domestic mining, of which 77% came from Bayan Obo ores and bastnaesite ores; 2) lanthanum has a wide variety of functional materials, and the most of the 28-year cumulative amount of lanthanum were used in petroleum cracking catalysts that consumed 47% of the total application of lanthanum; 3) from 1990 to 2018, China exported 292,000 tons of lanthanum, mainly smelting and separating products, to other countries; and 4) between 1990 and 2018, China's lanthanum was generally in excess but a small amount of insufficient supply occurred in 2013-2017 due to the significant export of lanthanum oxide and the growth of downstream applications, which was conducive to reducing inventory and promoting supply and demand balance. Based on these results this study suggests vigorously developing new materials and expanding new applications based on consolidating existing downstream consumption. In addition, to prevent environmental pollution, it is necessary to establish a recovery mechanism for waste petroleum cracking catalysts as soon as possible and formulate relevant laws and regulations.

The China-U.S. trade dispute has triggered worries about rare earth trade and the future of rare earth trade between U.S. and China has received public attentions. On the basis of analysis of the rare earth trade status between China and U.S. this paper constructs trade network models for rare earth compound, metal and permanent magnets to identify both direct and indirect trade paths between China and U.S., estimate path stabilities and the lowest transport costs, and analyze the future trend of rare earth trade between China and U. S. The results show that (1) the patterns of rare earth trade between the two countries will develop in different directions, each role of international division of labor will be more characteristic; (2) the limitations on rare earth trade are becoming weak as the paths between the two are enhanced; (3) rare earth import dependencies of China and U.S. will appear more complementary, which may provide an opportunity for both to develop cooperation in rare earth industry and trade. Based on these results, suggestions on strengthening cooperation and boosting industrial upgrading for China’ s rare earth industry and rare earth trade policies are provided.

This paper combs the actions for the United States, Japan and Europe to restructure their rare earth supply chain, analyzes the motivation and possibility of the reconstruction, and identifies its impact on the development of China's rare earth industry. The following conclusions are drawn. 1) through reconstructing supply chain, the United States, Japan and Europe have initially established a rare earth resource supply chain system independent of China; 2) the theoretical basis of the reconstruction, which is a long-term strategy, is to maintain their comparative advantages in high-end rare earth applications, and the practical basis is to ensure supply security for their industries; 3) to reconstruct the rare earth supply chain, they continue to resume their rare earth mines, the pattern of rare earth supply being changed greatly and gradually becoming diversified and China's dominant position in the supply being gradually decreased; 4) according to the output of rare earth permanent magnet materials and the neodymium iron boron magnetic materials consumed by new energy vehicles, it is predicted that the demand for rare earth will reach more than 600000 t by 2030 while the supply will be only 350000 t, far less than the demand, and the gap will become larger and larger as time goes by. Moreover, corresponding suggestions are put forward for China to improve the competitiveness of its whole rare earth industry chain.

To clarify the strategic significance of the flow, stock, and supply and demand patterns of lithium metal in new energy vehicle batteries and to guarantee the national energy transition and development of new energy vehicles, a Chinese lithium material flow analysis framework based on whole life cycle is constructed. The evolution of flow, stock, and supply and demand patterns of lithium elements driven by new energy vehicles in China from 2000 to 2020 is analyzed. The conclusions are as follows. Firstly, from the perspective of flow rate, lithium supply was dominated by lithium ore supply from 2000 to 2020;.the usage of the primary resources (349000 t) had a large increase while the supply of secondary resources (8000 t) was small; the driving force for the processing and usage of all kinds of lithium products changed from traditional lithium industrial products and 3C products (mobile phones, tablets, and laptops) to new energy vehicles. Secondly, from the perspective of stock, the stock of lithium products in use increased differently, among which the growth rate of power battery products ranked the first (an increase of 72000 t in 20 years), and the recycling potential was relatively large (less than 5% at present). Thirdly, from the perspective of the supply and demand pattern, the external dependence of lithium ore in China was relatively high (above 75%) and would remain high; China mainly imported industrial-grade lithium carbonate from developing countries in South America, and exported battery-grade lithium hydroxide to developed countries such as Japan, South Korea, and the United States.

To reveal the trend of material flow patterns at different stages of nickel resources in China, a life-cycle material flow analysis framework of nickel is constructed based on the dynamic material flow analysis method, and the change of material flow patterns at different stages of nickel resources in China from 2000 to 2020 is calculated and analyzed. The results are as follows. From a production perspective, nickel ore demand recovered under the new energy transition with nickel recovery being 20.4% in 2020. From a consumption perspective, the battery industry in the processing stage surpassed the electroplating industry to become the second nickel consuming sector while nickel consumption of manufacturing stage in the industrial sector decreased to 28.9% in 2019, and nickel consumption of new energy vehicles increased from 4275.0 t in 2015 to 16000 t in 2020. From a trade perspective, in recent years all stages of China except manufacturing and processing stages were net imported, among which net import products of nickel and iron increased rapidly from 105.7 t in 2000 to 413000 t in 2020, with a reduction of net export stainless steel from 213000 t in 2016 to 109000 t in 2020. From a stock perspective, the change in the in-use stock of terminal consumer goods was mainly driven by the transportation industry and construction and infrastructure, and the in-use stock of new energy vehicles increased by 131 times in five years.

In order to clarify the supply and demand situation of cobalt resources in China, material flow was used to analyze the changes in the flow, stock and supply and demand pattern of cobalt resources in China during 2000—2020. This article shows that 1) the import volume of cobalt ore to China was increasing year by year and the degree of external dependence was high, i.e., more than 70% yearly, and refined cobalt production and net exports increased year by year, reaching 85000 t and 14000 t, respectively in 2020; 2) the production of cobalt products was increasing from 100 t in 2000 to 63000 t in 2020, and batteries were the main cobalt products; in the trade phase, cobalt products showed a net export of 17000 t in 2020; 3) the stock of cobalt products in use continued to rise, reaching 125000 t in 2020. On the other hand, the overall recovery rate of cobalt products has been low, and improvement in recycling is the primary way to cope with the expansion of cobalt demand. At the same time, the article suggests improving the technical level, reducing the waste during processing process, reducing the dependence of cobalt resources, and doing an excellent job in resource reserve to adapt to the change of the international situation.